Various solutions have been studied and proposed, such as the application of “draining” asphalts that prevent the pooling of water, or the construction of tyres with particular tread designs. However, if there is an excessive quantity of water, the drainage of the asphalt is not guaranteed, and the normal wear of the treads progressively reduces their capacity to expel water.
A different approach to solve the aquaplaning problem lies in the use of devices that are mounted close to the wheels of the vehicle, particularly the driving wheels, and that shoot jets of liquid or gas onto the road surface to remove the layer of water that pools on such surface. Devices of this type also make it possible to clean, within certain limits, the road surface from different materials present there, such as sand, leaves and litter in general.
The most recent document that describes a device such as those mentioned above is European Patent EP 2 058 141. This device consists substantially of at least a nozzle, arranged in a fixed position on the vehicle near a respective tyre and fed with a pressurized gas contained in a suitable tank. The tank is connected to a compressor and is provided with a control valve. In addition, a series of deflectors, parallel to or slightly inclined with respect to the trajectory of the water raised and ejected by the tyre, are positioned along the perimeter of the wheels. The duct that delivers the compressed gas to the nozzle is also connected to a dynamic air intake, mounted on the front of the vehicle.
The solution of the EP 2 058 141 patent presents various drawbacks.
The first is represented by the fact that the operation is ensured only when the vehicle is travelling a straight path. In fact, if a wheel is veered, the respective jet of gas remains fixed with respect to the vehicle, that is, it does not follow the path travelled by the wheel, with the result of worsening the aquaplaning problem, as it removes the water from an area of the road surface that is not reached by the wheel and ejects it to the area toward which the wheel is directed.
A second drawback of the EP 2 058 141 patent lies in the fact that the deflectors are fastened to the wheel wells and thus can easily become fouled with mud and general dirt, reducing their effectiveness to the critical point of completely obstructing the passage of water. Also, even the front dynamic air intake, although it is provided with a screen, is subject to clogging, making the system unstable and uncontrollable.
A further problem is due to the fact that said system works only in ideal and not real conditions, due to the many design factors that could alter its performance, including the theoretical overpressure generated by the dynamic air intakes in front of the bumper that is added to the pressure generated by the system. This overpressure is directly proportional to the speed of the vehicle, and also depends on the cleanliness of the filters contained in the ducting system.
Finally, the EP 2 058 141 patent allows for a continuous flow of gas to expel the water from the road surface. This solution is potentially very dangerous, due to the fact that when the anti-aquaplaning system is applied the vehicle would suddenly be in conditions of good roadway contact, that is, with a good grip on the pavement, which will force the driver to take an abrupt and immediate action to control the vehicle.
The international patent application WO 01/39992 describes a method and a device for improving the driving safety of a vehicle in case of water, snow or similar conditions on the roadway. Jets of air are used in front of the wheels, the jets being mobile and/or adjustable and being controlled by a data processing system on the basis of information from sensor means that detect the operating parameters (wheel positions, transversal acceleration, angular speed, etc.) of the vehicle. However, it is not anticipated that the jets will also be operated as a function of the conditions of the road surface. Moreover, the jets are operated in continuous mode.
The German patent application DE 3619191 describes a method and a device for improving the braking action of a vehicle, in particular on an icy roadway. The document envisages the ejection of granulated material through dispensers fastened to the frame in front of the vehicle wheels.